ambient Posted May 16, 2015 Share Posted May 16, 2015 Can anyone recommend something ? It needs to be able to reproduce my ambient stuff, also I'm going to be playing with a guitarist over the summer too, so that as well. Thanks Quote Link to comment Share on other sites More sharing options...
Mottlefeeder Posted May 16, 2015 Share Posted May 16, 2015 (edited) I don't know if you are into DIY, but you can run a car stereo amplifier in bridge mode to give about 90 watts into 8 ohms, and a 12v 7AHr lead acid battery will give you 3-4 hours of use in an acousic pub setting, or about an hour outdoors keeping up with with guitars and vocals through a small pa. The amplifier input will match the output of an active bass, and you can walk to a gig with a 1 by 10 speaker in one hand, the amp/battery assembly in the other, and a gigbag on your back. [url="http://s285.photobucket.com/user/Mottlefeeder/media/DSCF0972_zps22a94527.jpg.html"][/url] The speaker is 30*30*40cm (12*12*15 inches) and the amp 'plate' contains the battery in the box with the logo. Ignore any idiot that chips in with 'don't believe the specs of car amplifiers' - the better brands now quote true RMS outputs in the specification (as well as painting peak outputs on the casing). David Edited May 16, 2015 by Mottlefeeder Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted May 17, 2015 Share Posted May 17, 2015 PHil Jones Bass 'Double Four' with a laptop battery back?... Quote Link to comment Share on other sites More sharing options...
Mottlefeeder Posted May 17, 2015 Share Posted May 17, 2015 [quote name='Musashimonkey' timestamp='1431846953' post='2775415'] PHil Jones Bass 'Double Four' with a laptop battery back?... [/quote] I can't see anything on the PJ website to confirm that this will run on batteries - it appears to be a mains-only practice amp. The PJ Briefcase will take the same battery that I used in mine. David Quote Link to comment Share on other sites More sharing options...
ambient Posted May 17, 2015 Author Share Posted May 17, 2015 [quote name='Mottlefeeder' timestamp='1431897350' post='2776079'] I can't see anything on the PJ website to confirm that this will run on batteries - it appears to be a mains-only practice amp. The PJ Briefcase will take the same battery that I used in mine. David [/quote] [quote name='Musashimonkey' timestamp='1431846953' post='2775415'] PHil Jones Bass 'Double Four' with a laptop battery back?... [/quote] Thanks guys, I wasn't aware that laptop batteries would power an amp. A few options there then Quote Link to comment Share on other sites More sharing options...
mcnach Posted May 17, 2015 Share Posted May 17, 2015 (edited) [quote name='Mottlefeeder' timestamp='1431897350' post='2776079'] I can't see anything on the PJ website to confirm that this will run on batteries - it appears to be a mains-only practice amp. The PJ Briefcase will take the same battery that I used in mine. David [/quote] The Double Four has a "DC input" on the front panel. That's where you can hook up a battery. If you look at the sort of batteries recommended for the Briefcase, they will work here too, you'll just need a suitable cable to hook it up, and a charger, presumably. Edited May 18, 2015 by mcnach Quote Link to comment Share on other sites More sharing options...
Mottlefeeder Posted May 17, 2015 Share Posted May 17, 2015 Just seen McNach's reply - in mitigation I would point out that the specification does not mention a battery power supply, and the socket is only listed as an input socket! [quote name='ambient' timestamp='1431898152' post='2776089'] Thanks guys, I wasn't aware that laptop batteries would power an amp. A few options there then [/quote] Laptop batteries contain lithium cells which can explode when abused. They also operate at voltages which are different to car batteries etc. I would be very wary about connecting a laptop battery to anything that was not specifically designed for it. You would also need to work out a safe way of charging it. Decent car amplifiers are designed to connect to 12-14 volts, and contain voltage convertors to provide the higher voltages needed to give you a higher power output - they tend to shut down if the applied voltage is not what they expect to see. A laptop power supply runs at about 19 volts, so it is unlikely that the laptop battery will provide enough voltage to give you enough power from a simple amplifier, or to allow a car amplifier to turn on. A 7AHr lead acid battery will cost you about £15, The same amount of energy in NiMH 'D-cells' will cost you about £80, and in Lithium-whatever will cost you well over £100. Your lightest option is lithium, but your cheapest option is a small lead acid battey, or if you want a longer gig, a larger lead acid battery and a trolley. Another option is to use a mains invertor to run your mains-amp from a 12 volt battery, This minimises the amount of new kit you need to buy, and allows you to use gear whose tone you already know and like. However, some basses and/or amps pick up a buzz from the invertor, so it is definately a try before you buy option. Piezo pickups and class D amplifiers seem to be better, The standby current for the invertor and amp is likely to be 1-2 Amps, which will mean you get less playing time out of that system than you would out of a system specifically designed for battery use, but it is a cheap way forward. Having said all that, some bass players have been very happy with Roland amplifiers running off 6 AA batteries http://www.roland.com/products/micro_cube_bass_rx/ - I was not impressed when I tried one, but it may have had half-dead batteries, or just not been capable of producing the sound I wanted. David Quote Link to comment Share on other sites More sharing options...
mcnach Posted May 18, 2015 Share Posted May 18, 2015 [quote name='Mottlefeeder' timestamp='1431904086' post='2776137'] Just seen McNach's reply - in mitigation I would point out that the specification does not mention a battery power supply, and the socket is only listed as an input socket! [/quote] Ha! I know, you'd imagine they would make that feature clear in their specs, eh? I also missed it for a while until someone else mentioned you could use that as a portable battery operated solution, and I went "huh?"... then I checked, and there it was Quote Link to comment Share on other sites More sharing options...
mcnach Posted May 18, 2015 Share Posted May 18, 2015 [quote name='Mottlefeeder' timestamp='1431904086' post='2776137'] Laptop batteries contain lithium cells which can explode when abused. They also operate at voltages which are different to car batteries etc. I would be very wary about connecting a laptop battery to anything that was not specifically designed for it. You would also need to work out a safe way of charging it. Decent car amplifiers are designed to connect to 12-14 volts, and contain voltage convertors to provide the higher voltages needed to give you a higher power output - they tend to shut down if the applied voltage is not what they expect to see. A laptop power supply runs at about 19 volts, so it is unlikely that the laptop battery will provide enough voltage to give you enough power from a simple amplifier, or to allow a car amplifier to turn on. A 7AHr lead acid battery will cost you about £15, The same amount of energy in NiMH 'D-cells' will cost you about £80, and in Lithium-whatever will cost you well over £100. Your lightest option is lithium, but your cheapest option is a small lead acid battey, or if you want a longer gig, a larger lead acid battery and a trolley. Another option is to use a mains invertor to run your mains-amp from a 12 volt battery, This minimises the amount of new kit you need to buy, and allows you to use gear whose tone you already know and like. However, some basses and/or amps pick up a buzz from the invertor, so it is definately a try before you buy option. Piezo pickups and class D amplifiers seem to be better, The standby current for the invertor and amp is likely to be 1-2 Amps, which will mean you get less playing time out of that system than you would out of a system specifically designed for battery use, but it is a cheap way forward. Having said all that, some bass players have been very happy with Roland amplifiers running off 6 AA batteries [url="http://www.roland.com/products/micro_cube_bass_rx/"]http://www.roland.co...o_cube_bass_rx/[/url] - I was not impressed when I tried one, but it may have had half-dead batteries, or just not been capable of producing the sound I wanted. David [/quote] Very informative! Thank you! Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted May 18, 2015 Share Posted May 18, 2015 I'll take a photo and forward the battery pack details I'm using with my PJB double four, later tonight when I get home. Nothing on their website, can't remember how I originally found out about it... It's sold as an external battery pack for 'laptops', runs at 20v I think, and best of all, slides nicely into the handle. The Double Four has lots of low end too, and sounds great, very impressive from such a small amp! It came with a range of connection adaptors and you can charge it with the power pack from the Double Four I believe, though I've got an old Sony laptop PSU laying around I use to charge it. Quote Link to comment Share on other sites More sharing options...
TPJ Posted May 18, 2015 Share Posted May 18, 2015 There are these too, a little different from the Roland [url="http://www.amazon.co.uk/gp/product/B009L4KZ8I?colid=2UEM3I3QG0K8R&coliid=I3R79FDF321TIB&ref_=wl_it_dp_o_pd_S_ttl"]Battery operated PA[/url] Quote Link to comment Share on other sites More sharing options...
Mottlefeeder Posted May 18, 2015 Share Posted May 18, 2015 [quote name='Musashimonkey' timestamp='1431937798' post='2776268'] I'll take a photo and forward the battery pack details I'm using with my PJB double four, later tonight when I get home. Nothing on their website, can't remember how I originally found out about it... It's sold as an external battery pack for 'laptops', ... [/quote] OK, that's a different ball game - that battery pack will have the fuses and over-temperature sensors built in to it - a battery pack borrowed from a laptop probably won't. David Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted May 18, 2015 Share Posted May 18, 2015 My fault in original description. It's an external additional power supply for laptops. But works great with the double four. Quote Link to comment Share on other sites More sharing options...
ambient Posted May 18, 2015 Author Share Posted May 18, 2015 Thanks for all your replies guys I'm gonna get a PJB Briefcase combo, would work for both small jazz gigs and busking Quote Link to comment Share on other sites More sharing options...
Musashimonkey Posted May 18, 2015 Share Posted May 18, 2015 You're more than welcome! There's one in the classifieds now! Quote Link to comment Share on other sites More sharing options...
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